The proportion of investment in solar projects worldwide is faster than ever, and the focus on return on investment remains the focal point of any project. In some cases, contractors will specify ordinary PVC cables instead of dedicated solar PV cables in order to save costs. Doing so may initially save costs, but will greatly affect the life of the system.
The characteristics of photovoltaic cables are determined by the unique insulation and jacket material - XLPE. After being irradiated by a radiation accelerator, the molecular structure of the cable insulation material changes and provides specific properties at high temperatures. In addition to performance at high temperatures, these cables are also cold, oil resistant, acid/alkali resistant, and overall will provide a long service life for the solar system.
Insulation: Irradiation XL polyolefin
Sheath: Irradiation XL polyolefin
Ordinary cable:
Conductor: Copper
Insulation: PVC or XLPE
Sheath:PVC
The conductors used in photovoltaic cables are basically the same as those used in ordinary cables. Photovoltaic cables have higher insulation and jacket specifications for use in harsher environments.
In solar power stations, photovoltaic cables need to be laid in harsh environments such as high temperature and ultraviolet radiation all year round. In places with good light conditions, the site temperature of the solar system can reach as high as 100°C on a sunny day. This creates high UV radiation, which normal cables cannot withstand for long periods of time. Ordinary cables cannot withstand such high DC voltages for a long time, and photovoltaic cables are required.
Most problems in photovoltaic systems come from incorrect cable selection and incorrect crimping techniques. These are often the root causes of fires in PV systems, so proper attention to cable selection is required.
A central element of PV system design is the matching between cables and DC connectors. Proper mating ensures a more accurate crimp, providing better contact between the cable and the DC plug. Oxidation due to inaccurate crimping can lead to increased contact resistance, which can cause disasters.
The copper conductors of common cable routing vary widely and are less compatible with DC connectors. Oxidation inevitably occurs after long-term wear, resulting in increased contact resistance.
In photovoltaic systems, most of the problems come from the DC side and more than 90% of the problems come from incorrect cable selection and crimping problems. For long-lasting, trouble-free system operation, it is critical to spend time and effort on compatible high-quality PV cables during the design phase.